After a study showed that watching nature videos can have positive benefits for inmates, some prisons are adding them to their lineup.

Inmates held in solitary confinement live up to 23 hours of each day in a tiny cell with limited contact with other humans. The practice has been found to lead to adverse behavioral effects in inmates, including anxiety, depression, hopelessness and violent outbursts.

Mostprisoners in solitary lack access to fresh air and natural light. But according to a recent study, those things can be simulated to improve their behavior and well-being.

A study published in the journal Frontiers in Ecology and Environment in September found that inmates who were shown nature videos for 45 minutes up to five times a week exhibited a 26 percent reduction in discipline referrals. Nearly half of the inmates reported improved moods that lasted for several hours after watching the videos, and 80 percent of them said the videos made their time in solitary easier to bear.

The study was carried out at the Snake River Correctional Institution in Oregon, a maximum security facility where inmates in solitary confinement are only let out of their cells to exercise in an indoor room once a day for about 45 minutes.Snake River reached out to the study's author, Nalini Nadkarni, after seeing her TED Talk on bringing nature and science into prisons, says co-author Tierney Thys, a research associate at the Cal Academy of Sciences.

“Both Nalini and I, our motto is put nature where it’s not,” Thys says. “My background is as a filmmaker [for National Geographic] and a marine biologist. I’ve seen that time in nature has a therapeutic aspect that is underappreciated."

Researchers gave 24 male inmates the option to view nature videos during their time in the indoor exercise room (later nicknamed the “Blue Room” for the blue glow of the projected videos). They displayed images of oceans, forests, rivers, deserts and rain. Some of the videos had ambient noise, some were accompanied by music, and some were silent.Twenty-four other male inmates did not get the same option.

The study points to the possibility that exposure to nature in an artificial sense can play a part in reducing psychological stress for nature-deprived people. It builds on research conducted in 1984 by Roger Ulrich, who showed that people healing from gallbladder surgeries needed less pain medication and healed better when their bedside window had a view of trees.

For some experts on solitary confinement, the findings aren’t surprising.

“The idea that [nature videos] would be helpful makes real sense to me,” says Stuart Grassian, a psychiatrist who has conducted extensive research on the psychological effects of solitary confinement. “In any situation of restricted environmental stimulation, any enhancement becomes important and helpful, if it involves the anchoring of attention.”

In other words, he says taking solitary prisoners' minds off of their current situation is beneficial.

But Craig Haney, a psychology professor at the University of California, Santa Cruz who has also studied the effects of solitary confinement, isn't so sure.

“I haven’t read the study and I don’t want to comment endorsing it or not, but I’m very skeptical about whether something so modest would be effective at overcoming negative psychological effects that are so serious,” Haney says. “Whether people’s mood improves is a separate question from [that] of whether they’re suffering from how they’re being treated. The real question ought to be why are people being confined in an environment where they have no opportunity to be in real nature?”

To Haney's point, states are slowly reducing the use of solitary confinement. Colorado ended the practice for inmates with mental health issues. Courts in Massachusetts and Pennsylvania have limited the practice. New York's changes, reached as part of a class-action settlement, include exemptions for pregnant prisoners and requirements that inmates in solitary have access to mental health treatment. Some say they could serve as a national model.

Since the study was released, the authors have been approached by a few state and local corrections facilities that want to bring the practice to their prisons.

For its part, the Oregon Department of Corrections has expanded the Blue Room principle to other facilities. Staff created a nature channel at the women’s maximum security institution that's available on every inmate’s private television 24 hours a day, says Chad Naugle, sustainability programs manager at the Oregon Department of Corrections. The channel has also been set up on the communal TVs at the minimum security facility.

Most recently, the women’s prison has designated a “crisis unit” cell that acts as a Blue Room, where inmates in psychological distress can enter to relax and soothe themselves.

“We’re trying to find something for the female inmates because they have higher rates of self-harm," says Naugle. "Anything we can do to eliminate those costs and staff overtime is sustainable for the institution, and it’s also a safety thing. I am [also] hoping for an increased sense of well-being generally.”